AlN is a physically and chemically stable material, and since it also has outstanding characteristics such as insulating and piezoelectric properties, the material is used in a variety of applications. One illustration of how AlN is used would be the instance in which AlN thin films are employed as insulating barrier layers in tunneling magnetoresistive devices, which is set forth, for example, in Asahi et al., Applied Physics Letters 89, 232511 (2006). In the just-cited reference, the TMR effect is confirmed in GaCrN/AlN/GaCrN ferromagnetic semiconductor tunnel junctions, albeit at low temperature (77K).    Non-Patent Document 1: Asahi et al., Applied Physics Letters 89, 232511 (2006)